Specify --init filename/extension

[HeCorr]

Summary

I personally much prefer the .yaml extension over .yml, but it doesn't seem like I'm able to specify which one to use when initializing a Taskfile with --init, so I'm always forced to rename the file afterwards.

Suggestion

Either:

• add the -e, --extension flags that let me specify which file extension to use (either .yaml or .yml), or
• repurpose the existing -t, --taskfile flags to specify the target filename if --init is also present
  • maybe also support a wildcard for the filename? i.e. task -i -t *.yaml ➡️ Taskfile.yaml

[HeCorr]

I'm willing to give this a shot, please assign me.